Firing-terminal of blasting-guns.



E. Hmmm.A l FIRING TERMINAL 0F BLASTING GUNS.

APPLICATION. FIL-ED MAR. 28| 1917.

Paented Jan. 1, 1918.

WMM/woo ERNEST HUTTON, OF WAYLAND, KENTUCKY.

FIRING-TERMINAL OF BLASTING-GUNS.

Specification of Letters Patent.

Patented Jan. 1, 1918.

Application filed March 28, 1917. Serial No. 158,076.

To all whom z't may concern Be it known that L'ERNEST HUT'roN, a citizenof the United States, residing at Wayland, in the county of Floyd andState of Kentucky, have invented certain new and useful Improvements inF iring-Terminals for Blasting-Guns, of which the following is aspecification.

This invention relates to that class of blasting devices that arearranged to carry an explosive charge at one end, to push the charge tothe desired place in a bored hole, and to fire the charge.

It is an object of the invention to provide for a blasting-gun of thistype a charge holding` and firing terminal of improved construction thatis adapted to be inserted into the end of the cartridge-casing andthereby to hold the charge, that is reliable in performing the firingfunction, that may be cleaned easily, and that is readily re1novablefrom the gun for purposes of cleaning and repair of the parts.

lVhen read in connection with the description herein, the details ofconstruction and arrangement of parts contemplated by the invention willbe apparent from the accompanying drawing, forming part hereof, whereinan embodiment of the invention is disclosed, for purposes ofillustration.

While the disclosures herein now are considered to exemplify apreferable embodiment of the inventiomit is to be understood that it isnot the intention to be limited necessarily thereto in interpretation ofthe claims, as modifications within the limits of the claims can be madewithout departing` from the nature and spirit of the invention.

Like reference-characters refer to corresponding parts in the views ofthe drawing, of which Figure 1 is a plan view;

Fig. 2 is a longitudinal sectional view on the line 2-2,7Fig. 1; and

Fig. 3 is an end, view of the bushing.

Having more particular reference to the drawing, 4: designates the endportion of the barrel or rod of a blasting-gun, which is formed with aconcentric screw-threaded circular recess 5 opening to its end toreceive a portion of the tiring member.

The device includes a peripherally screwthreaded disk 6 screwed into therecess 5 to its inner end. The disk has integrally formed therewith andextending from its outer face a tapered or truncoconicallyshaped bushingformed of contractible firk` gers 7, the lingers being produced bycutting slots 8 longitudinally in the bushing from its free end to thedisk, whichlatter is the base of the bushing. A bore or passage 9extends axially through the disk and bushing.

The iringmember proper has an vannular shoulder 10 arranged to abut theend of the barrel or rod of the gun, and extending inwardly from thisshoulder there is a smaller exteriorly screwthreaded ring portionl 11arranged to be screwed into the recess 5 with its end abutting the disk6. 'A flattened diametrically-disposed portion 12, constituting afiring-pin, extends outwardly from the shoulder 10, it is formed with anopening 13 extending laterally therethrough from one flat-tened face tothe other, and it is somewhat pointed at its free end 111. The materialis gradually reduced in thickness by a groove 15 formed in each of theliattened faces from the pointed end to the edge .of the opening 13,whereby there is provided a somewhat pointed centrally-disposedrearwardly-extending spark-terminal 16.

The member is hollow from its threaded or inner end 11 to the opening13, whereby there is provided a passage 17 that is concentric with thebore 9 of the bushing. The

passage or bore 17 at its inner end ,portion is of funnel shape, orgradually reduces in size toward the opening 13, as shown at 18, and itconforms approximately to the exterior contour of the bushing formed bythe fingers 7, so that, when the ring portion 11 is screwed into therecess 5 toward the disk 6, the fingers are contracted toward oneanother. l

Of an electric circuit including a battery or other suitable source ofelectricity and a switch, one wire is grounded in the barrel or rod ofthe gun (these parts not being shown), and the other wire 19 of thecircuit is insulated and leads through the barrel or ine rod to theinner or firing end thereof, as is of common practice in the art. Thewire further leads through the opening in the bushing, wherein it isheld tightly by the contracted fingers 7 gripping the insulation, and itextends from the passage of the firing member to the opening 13 thereof,where its free end constitutes an uninsulated spark terminal 20 that isdirectly opposite to the terminal 16.

When a gun of which the device is a part is to be used, an explosivecartridge, such as shown by dotted lines in Fig. 1 and designated by A,is placed and held on the device by its flattened and pointed end beingforced into the end of the cartridge, and the latter is pushed by thegun to the bottom or inner portion of the hole in which it is to befired. During insertion of the device into a cartridge, or intoexplosive that previously may have been placed in the hole it that.method is followed, the terminal 20 ot the wire is protected by thematerial of the device on the opposite side oli' the opening, and thusliability of grounding of the terminal is obviated. Some ot theexplosive takes position in the opening 13.

Thereafter, the switch oi the electric circuit is closed and a. sparkthereby7 is caused to jump across the space between the terminal points16 and 20, the latter oi which is connected with the other wire of thecircuit by that wire being grounded in the barrel or rod of the gun.This explodes the charge.

The spark-points 16 and 20, by reason of that particular disposition inthe opening 13, are accessible easily for cleaning. Moreover, if throughsuccessive use the wireterminal 2O becomes burnt, worn, or broken oli",the iiring member may be unscrewed from the recess 5 and the grip of thelingers 7 on the insulation of the wire 19 thereby loosened. Then morewire may be drawn from the gun and insulation removed from its end,whereby a new terminal is provided, after which the tiring member againmay be screwed into place and the fingers thereby caused again to gripthe wire-insulation.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. A tiring member for blasting-guns having a attened free end portionadapted to be inserted into an explosive charge and having an openingextending therethrough in the line of its lesser dimension, there beingoppositely-disposed grooves in said end portion leading to said openingin gradually increasing depth whereby a spark-point is provided at theedge out the opening.

2. A firing device adapted to be attached at one end to a blasting-gun,having 'for accommodation of an electric conductor a longitudinalpassage formed with a. converging wall, and a member having contractibleexteriorly tapered lingers arranged to extend into said passage and tobe pressed by the converging wall thereof against and to hold theconductor.

3. A tiring device adapted to be attached at one end to a blasting-gun,formed in its outer portion with a transverse opening, and having apassage leading to said opening formed with a converging wall, and amember having contractible exteriorly tapered lingers arranged to extendinto said passage and to be pressed by the converging wall thereofagainst an electric conductor leading to said opening.

4. The combination, with a blasting-gun having a screw-threaded recessin its end, ot' a tiring device comprising a member in said recesshaving contract-ible exteriorly tapered lingers extending outwardlytherefrom, and a tiring member screwed at one end into said recess andhaving a transverse opening in its outer portion and a passage extendingfrom the inner end to said opening, said passage having a taperedportion arranged to receive said lingers and to press them toward oneanother, and an electric conductor held between said lingers andextending to said opening.

In testimony whereof, l aliix my signature.

ERNEST HUTTON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. C.

